During the operation of circular knitting machines and similar industrial textile equipment, large amounts of lint and fabric particles are generated. To keep such particles from interfering from the proper operation of the equipment, fan and blower systems are employed. In conjunction with circular knitting machines, a typical fan/blower unit employed includes a central vertical stalk or shaft to which a generally horizontally-extending arm is mounted by use of an appropriate rotary joint. A fan is mounted at the distal end of the arm, which is dimensioned to locate the fan proximate the circumference of the knitting machine with which it is utilized. As depicted in pending U.S. patent application Ser. No. 08/296,224 of Aug. 25, 1994 to one of the present inventors, the fan rotates about a horizontal axis as the arm and fan sweeps around the circumference of the knitting machine about the vertical axis of the central shaft. The combination of rotations typically provides efficient removal of the lint and other particles from the critical portions of the machine.
While such devices are well suited for removal of lint from the knitting machines, the fan units themselves become the target for lint and other particles, generated both by the action of the knitting machines as well as operation of the fan itself. The blast of air from the front surface of the fan creates a complementary reduced-pressure effect at the rear of the fan, attracting suspended lint and dust particles. These particles are drawn towards and through the fan, and settle on the exposed surfaces of the fan blades, its guard, and motor. As they collect they interfere with the proper operation of the fan unit.
Because it is often impractical or impossible to shut off the fan because of the resulting down time to the knitting machine with which it is used, cleaning of the fans is usually attempted while the fans are in operation. The cleaning methodology typically utilizes an air hose having a nozzle fastened to the end of a long pole or stick. The pole is held by a maintenance worker and attempted to be manipulated to bring the air hose nozzle into the proximity of the fan while it rotates and revolves to blow the accumulated lint and dust off the fan. More often than not, however, the pole collides with the fan, damaging both the hose and the fan. In addition, even when successful, such cleaning is of marginal efficiency at best, since it is very difficult for the maintenance worker, even if relatively skilled, to maintain the air spray at the rotating fan for a significant enough time to thoroughly clean the fan.
It is accordingly a purpose of the present invention to provide an apparatus for the automated cleaning of rotating fans such as are utilized in conjunction with circular knitting machines.
Another purpose of the present invention is to provide an apparatus which may be installed upon, or retrofit upon, a circular knitting machine fan unit to effect cleaning thereof.
Still another purpose of the present invention is to provide an apparatus which can provide controlled cleaning, by the use of compressed air, to the fan during operation.
Yet another purpose of the present invention is to provide a cleaning apparatus for such circular knitting machine fans which provides a continuously accurately aligned and projected air flow to efficiently remove lint and other particles from rotating fans.